Suddenly I'm seeing spontaneous disconnects in my iOS 7 app from my nRF51822 peripheral

RE: Suddenly I'm seeing spontaneous disconnects in my iOS 7 app from my nRF51822 peripheral

SorenKonekt — Tue, 17 Dec 2019 10:17:16 GMT

same issue here. seems like most of the issues like this one end up without any apparent solution. Is this because poster resolve this through private support tickets, or is there a core issue between some versions of IOS and NRF Bluetooth stack that no one really undestands? Worries me.

RE: Suddenly I'm seeing spontaneous disconnects in my iOS 7 app from my nRF51822 peripheral

Masamine Someha — Tue, 05 Nov 2013 09:01:06 GMT

Was this issue resolved? I have a similar situation where the connection disconnects when it is trying to discover the services. It seems to be connected to using an active oscillator from another processor. But all the bluetooth connection works once the service discovery completes.

RE: Suddenly I'm seeing spontaneous disconnects in my iOS 7 app from my nRF51822 peripheral

John — Thu, 24 Oct 2013 11:46:05 GMT

Hi Ole,

I'll let Don address creating the support case and providing the sniffer trace.

I can answer your question regarding Master Control Panel. I use the Master Control Panel extensively as I develop our embedded FW. The problem does not appear with the Master Control Panel. It appears to be some sort of interaction between the iOS Core Bluetooth and the Soft Device Stack. One observation I have made is that the Master Control Panel and Core Blue tooth have different methods to read out the services and characteristics immediately after the connection request/response.

RE: Suddenly I'm seeing spontaneous disconnects in my iOS 7 app from my nRF51822 peripheral

Ole Morten — Thu, 24 Oct 2013 09:12:58 GMT

It's hard to be specific on issues like these, but having access to the sniffer trace and/or source code would be useful. Have you tried recreating the problem with Master Control Panel?

Anyway, it seems that this isn't a good fit for this kind of question-and-answer site, so maybe it would have been easier if you could post this as a regular support case. Please include the sniffer trace when you do.

RE: Suddenly I'm seeing spontaneous disconnects in my iOS 7 app from my nRF51822 peripheral

Don — Mon, 21 Oct 2013 16:08:20 GMT

Never mind part of that last post, that particular disconnect occurred because the device had not seen any traffic in 15 seconds and disconnected on it's own. The earlier disconnect described occurred spontaneously.

RE: Suddenly I'm seeing spontaneous disconnects in my iOS 7 app from my nRF51822 peripheral

Bastiaan — Mon, 21 Oct 2013 16:06:02 GMT

I have a sniffer log file from a ComProbe sniffer that shows a termination happening, initiated by the peripheral. I could provide that, or a printout of a section of the trace, or a screenshot. Is there a way to upload files associated with this thread? (the editing tools plug in URL's but this file isn't available via URL)

RE: Suddenly I'm seeing spontaneous disconnects in my iOS 7 app from my nRF51822 peripheral

Guest — Mon, 21 Oct 2013 16:06:02 GMT

RE: Suddenly I'm seeing spontaneous disconnects in my iOS 7 app from my nRF51822 peripheral

Don — Mon, 21 Oct 2013 15:58:56 GMT

Hi Ole. John has answered questions 1 & 3, I'll answer # 2. The disconnect happens at random locations/times. Earlier today I had a disconnect occur in the midst of the connection attempt (Core Bluetooth told to connect, started that process but then disconnected). Here are the lines from our log file: 2013-10-21 09:32:34.604 HOBOmobile[164:4703] MXBLEDevice.m:(1182) connectPeripheral: Tell the Central Manager to connect to the target peripheral 2013-10-21 09:32:34.645 HOBOmobile[164:1f6f] MXBLEDevice.m:(1841) didConnectPeripheral: Connection to peripheral with UUID = D93F9E39-89AA-BC5F-B0FA-30745532D7EA successful 2013-10-21 09:32:34.647 HOBOmobile[164:1f6f] MXBLEDevice.m:(1844) didConnectPeripheral: Active peripheral is now = <CBPeripheral: 0x175c5800 identifier = D93F9E39-89AA-BC5F-B0FA-30745532D7EA, Name = "MX1101", state = connected> 2013-10-21 09:32:34.648 HOBOmobile[164:1f6f] MXBLEDevice.m:(1854) PID = 9218, is a supported Onset device, created MXLoggerMX1101 logger object 2013-10-21 09:32:35.068 HOBOmobile[164:1f6f] MXBLEDevice.m:(1880) didDisconnectPeripheral: Peripheral with UUID = D93F9E39-89AA-BC5F-B0FA-30745532D7EA disconnected, error = Error Domain=CBErrorDomain Code=6 "The connection has timed out unexpectedly." UserInfo=0x175dcf00 {NSLocalizedDescription=The connection has timed out unexpectedly.} 2013-10-21 09:32:35.073 HOBOmobile[164:1f6f] MXBLEDevice.m:(1887) didDisconnectPeripheral: Unexpected disconnection detected - cleaning up

In another test I encountered another disconnect that happened spontaneously after the connection was fully established and there had been some other communication with the peripheral. Suddenly, from the app's point of view, a spontaneous disconnect occurred. The last communication with the device happened at 11:14:36.839, then there was some idle time, then the disconnect. Here are the log lines for that one - the didDisconnectPeripheral method is the callback from Core Bluetooth:

2013-10-21 11:14:51.881 HOBOmobile[188:1f0b] MXBLEDevice.m:(1880) didDisconnectPeripheral: Peripheral with UUID = D93F9E39-89AA-BC5F-B0FA-30745532D7EA disconnected, error = Error Domain=CBErrorDomain Code=0 "Unknown error." UserInfo=0x16d9c820 {NSLocalizedDescription=Unknown error.} 2013-10-21 11:14:51.884 HOBOmobile[188:1f0b] MXBLEDevice.m:(1887) didDisconnectPeripheral: Unexpected disconnection detected - cleaning up

RE: Suddenly I'm seeing spontaneous disconnects in my iOS 7 app from my nRF51822 peripheral

John — Mon, 21 Oct 2013 15:27:07 GMT

Hi Ole,

I am working on the embedded FW portion of the project Don is asking about. I can answer questions 1 & 3 for you.

Currently the app_error_handler is doing a reset. I will modify the code to assert and lock up so we can catch it in the debugger easily.

Our low frequency oscillator is +/- 20 PPM for its accuracy at 25C. When I call BLE_STACK_HANDLER_INIT, I pass it NRF_CLOCK_LFCLKSRC_XTAL_20_PPM.

Regards, John

RE: Suddenly I'm seeing spontaneous disconnects in my iOS 7 app from my nRF51822 peripheral

Ole Morten — Mon, 21 Oct 2013 14:25:35 GMT

This error is just a general connection timeout error, which can be caused by a lot of factors. First of all, I'd recommend you to make sure that app_error_handler does not contain a reset, since this will easily mask errors that could be returned by the softdevice.

Secondly, it would be interesting to know if there is anything in particular that is happening when you see this kind of problems. Is it close to some specific time (5 s, 10 s, 30 s or similar) after connection, or is it just random?

Third, this can happen if your clock source is not precise enough. What kind of low-frequency clock do you use?

The only change I've noticed from iOS 6 to 7 affecting applications is that iOS no longer seems to downgrade a write to a write without response, but instead just fails to transmit the data. This can be a problem if you have a characteristic that have the Write Without Response property, but your app tries to do a normal Write. In this case, it seems to me that iOS 6 will "downgrade" the Write to a Write Without Response, while iOS 7 will just not transfer the data. This should however not cause a disconnection.

RE: Suddenly I'm seeing spontaneous disconnects in my iOS 7 app from my nRF51822 peripheral

Rich — Wed, 16 Oct 2013 21:47:13 GMT

We are seeing some kind of iO7 issue as well. An app that worked perfectly well in iOS with regard to core bluetooth is now unable to maintain connection. Unfortunately, I am working from the BTLE firmware side and don't know what the app is indicating. I would be interested in hearing about any resolutions you find. Rich